Exodus 19:19 New English Translation

¹⁹When the sound of the horn grew louder and louder,^[a] Moses was speaking^[b] and God was answering him with a voice.^[c]

Exodus 19:19 tn The active participle הוֹלֵךְ (holekh) is used to add the idea of “continually” to the action of the sentence; here the trumpet became very loud—continually. See GKC 344 §113.u.
Exodus 19:19 tn The two verbs here (“spoke” and “answered”) are imperfect tenses; they emphasize repeated action but in past time. The customary imperfect usually is translated “would” or “used to” do the action, but here continuous action in past time is meant. S. R. Driver translates it “kept speaking” and “kept answering” (Exodus, 172).
Exodus 19:19 tn The text simply has בְּקוֹל (b^eqol); it could mean “with a voice” or it could mean “in thunder” since “voice” was used in v. 16 for thunder. In this context it would be natural to say that the repeated thunderings were the voice of God—but how is that an answer? Deut 4:12 says that the people heard the sound of words. U. Cassuto (Exodus, 232-33) rightly comments, “He was answering him with a loud voice so that it was possible for Moses to hear His words clearly in the midst of the storm.” He then draws a parallel from Ugaritic where it tells that one of the gods was speaking in a loud voice.

New English Translation (NET)